AAAA is a domain name record, which is basically the IPv6 address of the web server in which the domain is hosted. The IPv6 system was intended to replace the existing IPv4 system in which each and every Internet protocol address is made up of four sets of decimal numbers which range from 1 to 255 e.g. 126.96.36.199. On the other hand, an IPv6 address has 8 sets of 4 hexadecimal digits - ranging from 0 to 9 and from A to F. The reason for this transformation is the significantly smaller amount of unique IPs the present system supports and the quick increase of gadgets which are connected to the Internet. An example of an IPv6 address is 2101:1f34:32e2:2415:1365:4f2b:2553:1345. If you want to direct a domain address to a machine that uses such an address, you need to set up an AAAA record for it, and not the widely used A record, that is an IPv4 address. Both records have the exact same function, but different notations are used, to distinguish the two types of addresses.